The image on the left is the original map look before I execute a config file (exec server.cfg for example) and on the right is after.

It seems that this only occurs when the config file contains lines that change settings, config files that only restart a round do not turn the world dark. This also only seems to happen on a few maps, mainly surf_greatriver_fix (which is shown in the screenshots above.)

The world turns dark on a dedicated linux server running sourcemod, but also occurs on a standard listen server.

Below is an example of a config file that turns the world black. If anyone could help me out with why the world turns black and how to fix it, that would be great.

The problem is that most custom maps set mat_fullbright to 1. The problem here is that this is a cheat.

When you execute config files that contain sv_cheats 0 in them, it will turn the map dark as it has set mat_fullbright to 0. This is why when executing some config files (ones that didn't have sv_cheats 0 in them) it had no effect.

The fix for this is to remove "sv_cheats 0" from any config files that you may want to run during gameplay. It is probably also safe to remove it from server.cfg also as I would assume the default value would be 0.